The present invention is directed to an apparatus for treating contact lenses. More particularly, the invention is directed to a stand-alone apparatus by which contact lenses can be cleaned and hydrated without the application of heat, mechanical agitation or cleaning chemicals to the lenses. The apparatus is single-use and disposable, and comprises a housing defining a pair of closeable liquid sealed lens containers within which the lenses are contained and brought into contiguous wetted contact with layers of reactive material during the treatment process.
Contact lenses have come into wide use for correcting a wide range of vision deficiencies or cosmetic use. Typically, such lenses are formed from a thin transparent plastic material shaped and dimensioned to fit over the cornea of the eye. The lenses include a concave interior first optical surface for contact with the eye, and an opposed and optically associated convex exterior second optical surface. The two surfaces together define a corrective lens medically prescribed for a particular eye.
Depending on the plastic material used to construct the lenses, the lenses may be either "hard" or "soft". Hard contact lenses, which are comparatively more rigid, are typically formed from a relatively hydrophobic material such as polymethylmethacrylate (PMMA). Soft contact lenses, which are comparatively more pliant, are typically formed from a relatively hydrophylic polymer such as hydroyethylmethacrylate (HEMA), which has the property of being able to absorb and bind a proportionately large amount of water within the polymer network. Soft contact lenses formed from such hydrophilic polymers, when hydrated, are more comfortable to wear than hard lenses because they better conform to the cornea of the eye and cause less irritation when worn for extended periods. For this reason, the great majority of contact lenses presently being prescribed are of the soft type.
Unfortunately, soft contact lenses while being worn may collect contaminants from the eye and its environment. These contaminants, for example, may include proteins and lipids from the tear fluid of the eye, and foreign substances such as cosmetics, soaps, airborne chemicals, dust and other particulate matter. Unless periodically removed, these contaminants may cause abrasion to the surface of the eye, may impair the visual acuity of the lens, and may serve as a nutrient media for potentially harmful microorganisms.
Furthermore, for wearing comfort it is necessary that soft contact lenses be maintained uniformly hydrated at all times. While on the eye, the moisture content of the hydrophilic material of the lenses is maintained by tear fluid. However, when the lenses are removed for an extended period, as for cleaning or while sleeping, the lenses may dry out and become irreversibly damaged unless they are externally hydrated.
Consequently, various apparatus and methods have been developed for cleaning and hydrating soft contact lenses. For example, cleaning apparatus has been provided wherein the lenses are submersed in a variety of liquid cleaning agents, such as surficants, oxidants, disinfectants, enzymatic cleaners, or abrasives. Other cleaning apparatus has been provided which included mechanically operated or electrically powered components for vibrating, rotating, abrading, scrubbing, heating, agitating, subjecting to ultrasonic energy, or otherwise mechanically manipulating the lenses to enhance the cleaning action of the cleaning agent.
Such prior apparatus have not been entirely satisfactory for various reasons, including lack of cleaning effectiveness with respect to certain of the various contaminants found on the lenses, undesirable complexity, excessive time required for use, and dependence on an external power source.
One apparatus which overcomes these shortcomings is described in U.S. Pat. No. 5,657,506. This apparatus utilizes a two-section lens container wherein the exposed surfaces of two sponge members, wetted with an ophthalmologically-compatible solution, and each having thereon a reactive layer formed of a highly porous non-abrasive relatively polymeric material such as polytetrafluoroethylene (PTFE), are brought into compressive engagement with the optical surfaces of an interposed contact lens whereby the reactive layers cause contaminants to migrate from the lens to the reactive layers.
The present invention is directed to an alternative housing construction from that described in the above-identified patent which is simpler to use and which can be more economically manufactured for single-use and disposal.
Accordingly, it is a general object of the present invention to provide a new and improved apparatus for cleaning contaminated contact lenses.
It is a more specific object of the invention to provide an apparatus for cleaning contaminated contact lenses which is simpler to use and more economical to manufacture.
It is a further object of the present invention to provide an improved disposable single-use apparatus for cleaning contaminated contact lenses wherein a rigid base member having recesses thereon is folded to form liquid-sealed chambers for containing the lenses while the lenses are being cleaned.
It is a further object of the invention to provide an improved self-contained apparatus for cleaning contaminated contact lenses wherein recesses containing a sponge members coated with a reactive material are provided on a rigid base member such that when the base member is folded chambers are formed wherein the optical surfaces of the lenses are received in a wetted environment in contiguous contact with the reactive layers and contaminants are attracted away from the lenses.